I asked one of my students to write a report about nudibranchs - he did and I thought it was really good (especially for 4th)I wanted to post it here so he could hear what actual divers had to say

Here it is:

Is this an alien? Is it a Pokémon? No, it is a sea slug! Even though “sea slug” sounds nasty, they are fascinating! The real name for this one pictured above is Glaucus Atlanticus, but it is also called ‘sea slug’ or ‘nudibranch.’

Blue DragonMy favorite nudibranch is nicknamed the “Blue Dragon.” Here are some facts that I find interesting about the Blue Dragon. These animals live in tropical waters. They can be found in the Indian and Pacific oceans; off the coasts of South Africa, Europe, Australia, and Mozambique.

The Blue Dragon’s coloring helps protect it. It is grey on its underside allowing it to camouflage with the ocean water when predators look up at it. The blue color helps it camouflage with the ocean surface when predators look down at it. The blue color might also reflect UV rays. The only predator of the nudibranch is another nudibranch.

When full grown, Blue Dragon sea slugs can only be up to 3 cm long, but they know how to get around. They actually float upside down! They float with a gas filled sac in their stomach. Every time they breathe, air fills into the sac.

The Blue Dragon nudibranch is a surface predator. It has a muscular foot that helps it cling to film on the surface of the water. When it finds small prey, the Blue Dragon swallows it with it’s large mouth. Did you ever think about eating poison? Well this creature does it all the time! The Blue Dragon is the main predator of Portuguese Man O’ War. It is immune to the Man O’War’s poison. When it floats up toward a Portuguese Man O’ War, the nudibranch actually chomps off its poisonous tentacles and then uses the poison to create its own poison defense! The Blue Dragon’s sting is actually more powerful than the Portuguese Man o' War. Isn’t that crazy! To see the Blue Dragon in action, click here.Nudibranch TypesThere are two kinds of nudibranchs: aeolids and dorids. On the back of the aeolids, like the Blue Dragon, there are brightly colored sets of protruding organs called cerata. Aeolids have many cerata over their back which are used for defense, as well as for breathing. In contrast, the dorids breathe through a "gill" shaped like an oval on their backs.

Hooded NudibranchHave you ever seen a stylish nudibranch? Well, there is a nudibranch with a transparent hood that looks like an umbrella with transparent tentacles on the edge of the hood. They aren’t my favorite nudibranch because they aren’t as colorful as other types and their body appears to be clogged with seaweed.

This nudibranch’s features aren’t just for style. The Hooded Nudibranch captures its prey with its hood. It eats zooplankton, small fish, and jellyfish. When it captures food, the hood closes and the tentacles hold the food in. Another feature the Hooded Nudibranch has is gills on its back, which help it breathe. I think it is cool that this nudibranch can slip off its gills if predators attack. The Hooded Nudibranch below has things on its head (see in blue box) where its ears would be that help it smell.

The Hooded Nudibranch stays on kelp because kelp attracts fish, but it doesn’t just stay put. It swims very gracefully. I think it looks like a mini shark when it is swimming. The Hooded Nudibranch lives in the Pacific ocean from southern Alaska to California. If you are lucky, you may even see one in our ocean! To see one swim, click here.

Clown DoridAnother beautiful Nudibranch is the Triopha Catalinae, aka the Clown Dorid. This nudibranch has a feather-like fringe, which are its gills. Unlike other dorids, the Clown Dorid can not retract this fringe all the way when it is disturbed by a predator.

Clown Dorids are similar to the Hooded Nudibranch. They both get their food near kelp, but Clown Dorids only eat bryozoan species, an organism found on kelp. Also like the Hooded Nudibranch, Clown Dorids live in the Pacific ocean, but more on the east side, near Japan and South Korea. They can also appear in the Pacific from Alaska to Mexico. In fact, they were named after the Santa Catalina Island, off of California.

One of the Clown Dorid’s most fascinating talents is the egg masses it lays. These masses look like a blooming flower. Each dot is an individual egg. Imagine how many eggs there would be if there were 10,000 little dots? These eggs hatch into plankton.

ConclusionIn conclusion, sea slugs come in many varies with many different attributes. However, they all have some way of moving, breathing, capturing their prey, and protecting themselves.

What is your favorite type of nudibranch? Please let me know in the comments section.Bibliography: